Who is that man, and why is Gerard Butler hugging him like there's no tomorrow? Sam Childers is the real-life inspiration for Butler's new movie, "Machine Gun Preacher," which costars Michelle Monaghan and had its U.S. premiere Wednesday night in Beverly Hills.

"Preacher" stars Butler as Childers, a drug-dealer-turned-preacher-turned-rescuer-of-orphans in war-torn Sudan. Monaghan plays Childers' wife, Lynn, whom he met during his wild days, when she was a stripper. Both later turned to the church, which put them on the path to Africa.

Pictures: 'Machine Gun Preacher' premiere

"I cry every time I watch it, especially the first part when I was not a good person," Childers told the Los Angeles Times at the Toronto International Film Festival, where the movie premiered.

"There are things in that movie that I tried to block out -- I started doing drugs when I was 11. I was a heroin addict. I sold drugs to my high school teachers -- and now it's out there. None of that was fabricated." He said more than 70% of the movie is true.

Butler -- who during filming carried with him pictures of children mutilated by fighters who for two decades have raided villages in southern Sudan in the dark of night -- worked for one-thirtieth his normal rate on the film.